There is a natural balance between the formation of free radicals during normal cellular metabolism and the endogenous antioxidant capacity of vertebrate cells that prevents the accumulation of free radicals. In situations where the levels of free radicals exceed the antioxidant capacity of the cell, however, oxidative stress may occur. Oxidative stress is essentially the toxic accumulation of high levels of free radicals, whereby the free radicals may damage the cells by oxidizing fatty acids of the cell membranes or interacting with DNA or proteins. High producing reproductive and growing animals are particularly prone to oxidative stress, and the situation appears to be exacerbated under certain environmental, physiological, and dietary conditions. Consequently, oxidative stress may compromise the health status and impair the production performance of such animals.
Dietary lipids such as supplemental fats, oil seeds, and distillers grains, if not stabilized, not only may contribute significantly to the load of free radicals in the animal, but also may negatively affect the growth of beneficial intestinal microflora. Thus, dietary antioxidants are useful for preventing the oxidation of dietary lipids in the final feed and for reducing free radical damage to the intestinal microorganisms and the animal. The endogenous antioxidant defense mechanism of the animal also depends upon other dietary nutrients, such as trace minerals and vitamins. Feeding adequate levels of trace minerals has been shown to benefit the health status of cattle by improving the immune response and antioxidant status, thereby leading to better animal performance. However, not all sources of trace mineral are equally available. Because of dietary antagonisms, organic trace minerals have been shown to have higher bioavailability than the inorganic forms. Furthermore, dietary organic acids have been shown to improve the microflora in the digestive tract, which may benefit feed and nutrient intake. Thus, there is a need for combinations of antioxidants, trace minerals, essential amino acids, and/or organic acids that can be readily mixed with animal feed rations for the improved health and antioxidant status of the animal, as well as increased production performance of the animal.